In two parts, on two wonderful painted cards, this "Buttje, Buttje.. ...in de See" came swimming to Oldenburg!

The line concerning the "(golden) flounder
in the sea" comes from the German fairy tale "Von den Fischer und
siine Fru (1812), that is, "The Fisherman and His Wife", one of the
tales collected by the Brothers
Grimm (in the Netherlands knows as "Piggelmee").